问题描述
鄙人才学java的Struts第一个程序就出现了问题，头疼，高手指教！struts.xml:<?xmlversion="1.0"encoding="UTF-8"?><!DOCTYPEstrutsPUBLIC"-//ApacheSoftwareFoundation//DTDStrutsConfiguration2.0//EN""http://struts.apache.org/dtds/struts-2.0.dtd"><struts><constantname="struts.devMode"value="true"/><packagename="default"namespace="/"extends="struts-default"><actionname="hell"><result>/Hello.jsp</result></action></package><!--Addpackageshere--></struts>一加上<constantname="struts.devMode"value="true"/>就出错报错：严重:Exceptionstartingfilterstruts2java.lang.NullPointerExceptionatcom.opensymphony.xwork2.util.FileManager$FileRevision.needsReloading(FileManager.java:209)atcom.opensymphony.xwork2.util.FileManager.fileNeedsReloading(FileManager.java:60)atcom.opensymphony.xwork2.config.providers.XmlConfigurationProvider.needsReload(XmlConfigurationProvider.java:325)atorg.apache.struts2.config.StrutsXmlConfigurationProvider.needsReload(StrutsXmlConfigurationProvider.java:168)atcom.opensymphony.xwork2.config.ConfigurationManager.conditionalReload(ConfigurationManager.java:220)atcom.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:61)atorg.apache.struts2.dispatcher.Dispatcher.getContainer(Dispatcher.java:774)atorg.apache.struts2.dispatcher.ng.InitOperations.initStaticContentLoader(InitOperations.java:77)atorg.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:49)atorg.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)atorg.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)atorg.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)atorg.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3800)atorg.apache.catalina.core.StandardContext.start(StandardContext.java:4450)atorg.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)atorg.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)atorg.apache.catalina.core.StandardHost.addChild(StandardHost.java:526)atorg.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:987)atorg.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:909)atorg.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:495)atorg.apache.catalina.startup.HostConfig.start(HostConfig.java:1206)atorg.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:314)atorg.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)atorg.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)atorg.apache.catalina.core.StandardHost.start(StandardHost.java:722)atorg.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)atorg.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)atorg.apache.catalina.core.StandardService.start(StandardService.java:516)atorg.apache.catalina.core.StandardServer.start(StandardServer.java:710)atorg.apache.catalina.startup.Catalina.start(Catalina.java:583)atsun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethod)atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)atjava.lang.reflect.Method.invoke(Method.java:597)atorg.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)atorg.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)2010-8-1111:37:39org.apache.catalina.core.StandardContextstart严重:ErrorfilterStart2010-8-1111:37:39org.apache.catalina.core.StandardContextstart严重:Context[/Struts2_0100_Introduction]startupfailedduetopreviouserrors